Flow-type laboratory ozonolysis apparatus and method of performing ozonolysis reaction

ABSTRACT

A flow-type laboratory scale ozonolysis apparatus ( 100 ) according to the invention comprises a reservoir ( 104 ), a n feed pump ( 102 ), a mixing element ( 120 ) with two inlets and an outlet, a reactor unit ( 110 ) and a pressure-adjusting means ( 160 ), all connected into a flow path. The ozonolysis apparatus ( 100 ) further comprises an ozone source ( 110 ), as well as a dispensing valve ( 112 ) transmitting a gas stream only in a single direction and installed between the ozone source ( 110 ) and one of the inlets of the mixing element ( 120 ). The feed pump ( 102 ) of the ozonolysis apparatus ( 100 ) according to the invention is a liquid pump generating a constant volume rate, the reservoir ( 104 ) contains at least the substance, as a solute, to be subjected to the ozonolysis reaction and the reactor unit consists of first and second reactor zones differing in function from one another. In the flow path, the outlet of the first reactor zone is connected to the inlet of the second reactor zone. Furthermore, an inlet for feeding in substances is inserted into the flow path between the reactor zones, and the pressure-adjusting means ( 160 ) is installed into the flow path after the reactor unit and is provided with an electrically governed control.

The present invention relates to a flow-type laboratory scale ozonolysisapparatus comprising a liquid reservoir, a feed pump, a uniting elementwith two inlets and an outlet, a reactor unit and a pressure-adjustingmeans, all connected into a flow path, the apparatus further comprisingan ozone source and a dispensing valve transmitting a gas stream only ina single direction and being installed between the ozone source and oneof the inlets of the uniting element. The invention also relates to amethod of performing ozonolysis reaction of a given substance.

In the chemical industry, the term “ozonolysis”, in general, refers tothe oxidation of organic hydrocarbon compounds (in particular, ofalkenes and aromatic compounds) accompanied by a chain scission.Ozonolysis reactions represent chemical reactions that are relativelyrarely applied. Due to their hazardous nature, the ozonolysis reactionsare not spread in the field of industry, agriculture and therapy,however, they are widely used for disinfection and sewage treatment. Theozonolysis reactions usually comprise of two reactions that takeplace/are carried out one after the other. The exothermic reaction,accompanied by a strong generation of heat, of the organic substance andthe ozone mixed thereto takes place within a primary reaction. In asecondary reaction following the primary one, a further reaction(preferentially decomposition or stabilization) of the intermediate (theso-called ozonide) produced in the primary reaction takes place viaadding an additive thereto. To accomplish ozonolysis reactions, additionof gaseous ozone in a great amount is required. Due to the highexplosion risk and reactivity of the intermediate formed, theimplementation of ozonolysis reactions on the industrial scale is,however, possible only in that case if safety means of relatively highcosts are applied and proper safety measures are adhered to.Furthermore, the production of gaseous ozone in a necessary amountrequires the usage of a high performance ozonizer that also has largephysical dimensions.

European Patent No. 1,039,294 A2 discloses an ozone hydroxyl radicalanalyzer and a chemical assaying method accomplished by the analyzer.Said analyzer comprises a reaction channel with an inlet and an outletaccommodating an ozonolysis reaction, a feed pump for introducing asample through the inlet into the reaction channel to be analyzed bymeans of an ozonolysis reaction, an ozone generator feeding an ozonecontaining gas through the inlet into the reaction channel and a controlunit. The ozone generator, by the nature thereof, is built up ofconcentric tubular electrodes, on which high voltage is applied when isoperated. The ozone consumed in the reaction is generated by passing anoxygen containing gas through the electrodes carrying high voltage. Agiven amount of sample fed into the reaction channel is subjected to theassay by the analyzer which means that the analyzer is a batch-typeanalyzer.

German Pat. Publication No. 199 10 639 A1 discloses an apparatus forcleaning spent water, to be used preferably in a car washer, having anozone generator in the form of an electrolysis cell operated onelectricity. The apparatus can be equally put into a continuouslycirculated stream of water or into the water led out from the stream andcollected in a reservoir. The chemical reaction between thecontamination content of the spent water and the ozone that results inthe purification of water is performed within a reservoir of largedimensions storing said spent water to be treated by bubbling the ozoneproduced in the electrolysis cell sunk into the spent water to the spentwater and then by continuously rebubbling the not reacted ozone reachingthe water surface from a volume of the reservoir being above the watersurface back into the water.

International Publication No. WO01/40124 discloses a method and anindustrial scale apparatus for treating electronic components, such ase.g. integrated circuits, with an ozonated liquid substance. Saidapparatus comprises a vessel for accommodating and storing a stockfluid, an ozone source in fluid communication with the latter, anexhaust for discharging the ozonated stock fluid from the vessel, and aback-pressure regulator unit for regulating pressure within the vesseland for controlling opening/closing of the exhaust. The ozonated fluidis produced within the vessel by means of bubbling the ozone generatedby the ozone source into the liquid. To enhance efficiency of thetreatment, before the liquid exits through the exhaust the size of theozone bubbles of the ozonated liquid is decreased to at most about 50 μmby means of installing a suitably perforated member. However, noheterogeneous phase ozonolysis reaction takes place within theapparatus.

The above discussed solutions are either based on industrial scaleapparatuses or not flow-type ones. Furthermore, the known solutions canbe neither used during the discovery/compound finding phases ofpharmaceutical research.

In view of the above it is apparent that there would be a great need fordeveloping an ozonolysis apparatus that subjects tiny amounts of achemical substance to ozonolysis reaction in a controlled way and bymaintaining it in a continuous flow.

In light of the above, the object of the present invention is to developa flow-type ozonolysis apparatus capable of accomplishing the aimedozonolysis reaction in a safe and convenient manner, as well as with ahigh reaction yield as a consequence of the amount of reactants beinginvolved in the ozonolysis reaction carried out therein in a controlledmanner. A further object of the present invention is to provide anozonolysis apparatus that can be cheaply manufactured and hence widelyused in the laboratory practice due to the low manufacturing costs ofits major components, that is the ozone source and the reactor unitthemselves. A yet further object of the present invention is to providea safe process for ozonolysis reactions. Further objects of the presentinvention will be apparent from the detailed discussion of the solutionaccording to the invention.

In one aspect of the present invention, the above objects are achievedby a flow-type laboratory scale ozonolysis apparatus, wherein the feedpump is a liquid pump generating a constant volume rate, the liquidreservoir contains at least the substance, as a solute, to be subjectedto the ozonolysis reaction and the reactor unit consists of first andsecond reactor zones being different as to their function, wherein theoutlet of the first reactor zone is connected to the inlet of the secondreactor zone in the flow path and a sub-stance intake is inserted intothe flow path between the reactor zones, and the pressure-adjustingmeans is connected into the flow path after the reactor unit and isprovided with an electrically governed control.

Preferred embodiments of the apparatus according to the presentinvention are defined by dependent claims 2 to 18.

In a further aspect of the present invention, the above objects areachieved by providing a method of performing laboratory scale ozonolysisreaction of a given substance, comprising the steps of supplying a givenamount of substance being solved to be subjected to ozonolysis reactionby means of a feed pump into a flow path; feeding ozone through adispensing valve into the flow path in a section located after thesubstance supplying position; leading solved substance through a reactorunit comprising first and second reactor zones arranged in a section ofthe flow path located after the ozone feeding position; supplying anadditive needed for the completion of ozonolysis reaction into the flowpath after the first reactor zone of the reactor unit; maintaining thepressure of the reaction in a given pressure range by means of apressure adjusting means arranged in the flow path after the reactorunit; collecting the product generated in the second reactor zone of thereactor unit in a product receptacle connected to the end of the flowpath.

Preferred embodiments of the method according to the invention arespecified by dependent claims 20 to 24.

The invention will now be described in detail with reference to theaccompanying drawing, wherein

FIG. 1 shows a schematic block diagram of an embodiment of thelaboratory scale ozonolysis apparatus;

FIG. 2A shows a sectional view of a possible embodiment of an ozonegenerating electrolysis cell used within the ozonolysis apparatusaccording to the invention;

FIG. 2B illustrates schematically the electrode structure of the ozonegenerating electrolysis cell of FIG. 2A;

FIG. 3A shows a sectional view of a possible embodiment of amicrofluidic reactor to be preferentially used within the ozonolysisapparatus according to the invention; and

FIG. 3B illustrates a sectional view along the line A-A of themicrofluidic reactor shown in FIG. 3A.

Referring now to FIG. 1, ozonolysis apparatus 100 schematically shown inFIG. 1 comprises a liquid reservoir 104 equipped with a feed pump 102,uniting elements 120, 140, a reactor unit comprising a first reactor 130with a reaction channel 135 and a second reactor 150 with a reactorchannel 155, a pressure-adjusting means 160, a product receptacle 180, acontrol unit 190, a dispensing valve 112 and an ozone source 110. Theozonolysis apparatus 100 further comprises a liquid reservoir 174equipped with a feed pump 172. The inlet of the feed pump 172 is in flowcommunication with the liquid reservoir 104, while its outlet isconnected to a first inlet of the uniting element 120 inserted into apipe 106. Through a pipe 114 and the dispensing valve 112 inserted intothe pipe 114, the ozone source 110 is connected to a second inlet of theuniting element 120. The outlet of the uniting element 120 is connectedto the inlet of the reaction channel 135 of the first reactor 130. Theoutlet of the reaction channel 135 of the first reactor 130 is connectedto a first inlet of the uniting element 140 inserted into a pipe 107. Toa second inlet of the uniting element 140 the outlet of the feed pump172 is connected, optionally through a pipe 176. The inlet of the feedpump 172 is in flow communication with the liquid reservoir 174. Theoutlet of the uniting element 140 is connected to the inlet of thereaction channel 155 of the second reactor 150. The outlet of thereaction channel 155 of the second reactor 150 opens into the productreceptacle 180 through a pipe 108 and the pressure-adjusting means 160inserted into the pipe 108. As a result of connecting the specifiedelements to each other, the ozonolysis apparatus 100 will be possessedof a continuously connected flow path running from the outlet of thefeed pump 102 to the inlet of the product receptacle 180.

Through leads 191, 192, 195, 197, the programmable control unit 190 isin electrical connections with the feed pump 102, the dispensing valve112, the feed pump 172 and the pressure-adjusting means 160,respectively.

The liquid reservoir 104 contains the substance, and/or its solution(from now on, referred to as sample solution in brief) to be subjectedto an ozonolysis reaction. If performing the ozonolysis reactionrequires the presence of a catalyst, the catalyst, in a suitable form,is mixed to the sample solution, and hence it is also present within theliquid reservoir 104. Feeding of the sample solution (optionally alsocontaining the catalyst) into the flow path is performed by the feedpump 102. The feed pump 102 is preferably provided by a HPLC pump thatis adapted for maintaining a continuous flow of the sample solution witha constant flow rate. Actually, the HPLC pump is a precision pump thatoperates with a constant feed rate, set as desired, in the presence ofthe pressure created and continuously maintained by thepressure-adjusting means 160; the feed rate can be, of course,arbitrarily varied.

The liquid reservoir 174 contains the additive, that is, the substanceand/or a solution thereof (from now on, referred to as solution ofadditive in brief) needed for the decomposition/stabilization of theintermediate produced in the ozonolysis reaction. If performing a secondreaction needed for decomposing/stabilizing the intermediate requiresthe presence of a catalyst, the catalyst, in a suitable form, is mixedto the solution of additive, and hence it is also present within theliquid reservoir 174. Feeding the solution of additive (optionally alsocontaining the catalyst) into the flow path is performed by the feedpump 172. The feed pump 172 is preferably also provided by a HPLC pumpthat is adapted for maintaining a continuous flow of the solution ofadditive with a constant flow rate. The feed rate provided by the HPLCpump can be, of course, also arbitrarily varied.

The uniting elements 120, 140 are preferably T-shaped elements that aremade of a plastic material with a chemical resistivity against reactiveozone, preferably a fluorinated and/or chlorinated polymer, morepreferably polytetrafluoroethylene (PTFE). In a possible furtherembodiment, only the inner surfaces of the flow channels of the unitingelements 120, 140 are made of or coated with the chemically resistantplastic material. To facilitate the diffusion limited ozonolysisreaction taking place within the first reactor 130, the uniting element120 blends the sample solution and the pressurized ozone enteringthrough the inlets thereof. A sample solution with ozone bubbles exitsthrough the outlet of the uniting element 120. The uniting element 140blends the intermediate produced within the first reactor 130 and theadditive taking part in a second reaction required to decompose orstabilize the intermediate itself. The uniting elements 120, 140 can be,of course, formed as any other members that ensure the proper mixing ofthe liquid and gaseous reactants fed into the uniting elements 120, 140.

The dispensing valve 112 on the one hand restrains the backflow of thesample solution to the ozone source 110 and on the other hand performsthe feeding of ozone. The dispensing valve 112 is preferably anelectronically controlled on/off switch valve preferentially made ofPTFE that is actuated by the control unit 190. As far as the efficiencyof the diffusion limited reaction between the sample solution and theozone is concerned, the size of the contact surface between thereactants is of the greatest importance. Accordingly, the dispensingvalve 112 is designed to dispense bubbles of the least possible size,preferably with the size of about 10 μl, that is, microbubbles. If thesize of the ozone bubbles dispensed by the dispensing valve 112 is toolarge from the point of view of the reaction planned, an end sheet (notshown in the drawing) preferably made of PTFE with perforations ofdesired diameter is arranged at the ozone access inlet of the unitingelement 120 to decrease the size of the ozone bubbles being mixed intothe sample solution.

As is well-known, gaseous ozone is of extraordinary hazard, itshandling, in general, requires the usage of special means and adherenceto proper safety measures. Accordingly, in the present solution theozone gas consumed in the ozonolysis reaction is generatedpreferentially in-situ: the ozone is obtained preferably from water bymeans of electrolysis (i.e. by decomposition of water). Accordingly, inone of its preferred embodiments the ozone source 110 is formed as oneor more asymmetric pressure ozone generating electrolysis cells. FIG. 2Aillustrates a preferred embodiment of the ozone source 110 used in theozonolysis apparatus 100 according to the invention, formed as an ozonegenerating electrolysis cell 110′. The electrode structure 10 of FIG. 2Bused in the cell 110′ comprises a cathode 13, an ozone generating anode16, a proton exchange membrane 15 arranged therebetween and a firstelectrode support 17 arranged on a side of the anode 16 located oppositeto the membrane 15. The electrode support 17 is arranged on an (anodeside) bearing member 18 provided with a through-hole 19 for anelectrical contact. The cathode 13 is formed on a second (cathode side)electrode support 12 arranged in a (cathode side) bearing member 11.

The electrode support 12 serves on the one hand for providing electricalcontact between e.g. the DC power supply of the ozonolysis apparatus 100and the cathode 13 and on the other hand for directing the waterrequired for the electrolysis to the cathode 13 during the operation ofthe cell and diverting the produced hydrogen gas from the cathode 13.Accordingly, the electrode support 12 is formed as a member with highelectrical conductivity and a porous structure, as well as with highmechanical strength in order to tolerate the high pressures of up to 20bars that may develop inside the 110′ cell. In particular, the electrodesupport 12 is a thin and porous titanium frit arranged in the bearingmember 11 and produced by high-pressure cold moulding of titaniumgranulate. Here and from now on, by the term “frit” a material made of apowder of grains by cold moulding is referred to. The titanium granulatepreferably comprises three different sizes of titanium grains in alayered structure, in which the layers are arranged in the order of thegrain size in such a way that before moulding, a relativelycoarse-grained titanium powder (preferably comprising grains having adimension of 600-1200 μm) is put into the bearing member 11 to thebottom, then a titanium powder of medium sized grains (preferablycomprising grains having a dimension of 350-600 μm) is applied thereon,and finally, a fine-grained titanium powder (preferably comprisinggrains having a dimension of 150-350 μm) is applied thereon. Hence, thetitanium frit produced by moulding and the cathode side electrodesupport 12 made therefrom will have a grain size gradient in thedirection of depth.

The cathode side bearing member 11 is made of a special, chemicallyresistant plastic shaped to e.g. an annular member. It is obvious,however, that the bearing member 11 may be made of any other materialand may have any other shape as well.

An essential condition for the efficient cell operation is the goodelectrical contact between the cathode 13 and the anode 16, as well asthe membrane 15. Therefore, formation of the cathode 13 on the electrodesupport 12 made of the titanium frit has key importance. In theelectrode structure 10 of FIG. 2B, it is preferred that for the cathode13, extra fine-grained platinum powder (so called platinum black) isused.

The proton exchange (or proton conducting) membrane 15 is preferably inthe form of a sulphonylated, perfluorinated polymeric resin membrane,most preferably the polymeric membrane Nafion® of DuPont de Nemours, Co.The membrane 15 is the solid electrolyte of the cell 110′. In addition,the membrane 15 provides the separation of gases produced at the cathodeand the anode. The water required for the electrolysis is introduced atone side of the membrane 15, through the second electrode support 12provided with the cathode 13, whereas the gaseous mixture of oxygen andozone to be used is generated on the other side of the membrane 15, thatis, at the anode 16.

The anode 16 serves for supporting the anode side electrochemicalreaction. For the anode 16, electrically conducting metals, semimetalsand/or oxides thereof are used in general. The use of the oxides oftransition metals is advantageous because those are commonly availableand inexpensive. However, the mechanical strength of these oxides islow, thus they have to be placed on a substrate with high mechanicalstrength and chemical resistance against the highly corrosive gaseousmixture of oxygen and ozone so that said oxides could tolerate highpressures arising in the cell 110′ during operation without beingmechanically damaged.

For the electrode support 17 used to support the anode 16, noble metals(e.g. platinum) with good electrical conductivity or the alloys and/orthe mixture thereof are used. The electrode support is formed as asuitably perforated platinum sheet provided with through-holes havingpreferably a diameter of at least 0.8 mm.

The anode side bearing member 18 serves for removing the gaseous mixtureof oxygen and ozone generated at the anode 16 during operation of the110′ cell from the anode 16. The bearing member 18 is additionally usedto clamp the electrode support 17 to the anode 16 and the latter to themembrane 15 in order to provide a perfect electrical contact, as well asa homogenous transition surface therebetween. In the electrode structure10 shown in FIG. 2B, the bearing member 18 is made of a resilient,porous, chemically resistive material, preferably of PTFE frit producedfrom grained PTFE by high-pressure moulding. The bearing member 18 isprovided with a through-hole 19. In the assembled cell 110′ thethrough-hole 19 is adapted to receive an anode side conducting memberused for electrically connecting the anode side electrode support 17 andthe power supply.

In the ozone generating cell 110′ forming the ozone source 110 of theozonolysis apparatus 100 the anode 16 is made of a material with goodelectrical conductivity, plasticity, high evolution potential andchemical resistance against the highly corrosive gaseous mixture ofoxygen and ozone, preferably a mixture of lead dioxide and PTFEcomprising PTFE in an amount of at least 10% by weight. The mixture oflead dioxide and PTFE is produced from solid-phase raw materials atambient temperatures with no use of further additives. Before producingthe anode 16, the lead dioxide constituting a first component of themixture of lead dioxide and PTFE used as the material of the anode 16 issubjected to continuous crushing, which results in lead dioxide grainsof colloid size, i.e. with an average grain size of 0.5-100 μm, producedfrom the initial macroscopic sized lead dioxide pieces. For the othercomponent of the mixture of lead dioxide and PTFE used as the materialof the anode 16, solid PTFE filaments having a fibrous (cottonwool-type) structure and a thickness of 50-100 μm, as well as a lengthof up to 1 mm are used. The PTFE filaments with such dimensions can beproduced by abrasive machining or abrasion of a PTFE block.

In order to produce the material of the anode 16, lead dioxide crushedinto grains of colloid size in an amount of e.g. about 1600 mg and PTFEin the form of fine elementary filaments in an amount of e.g. about 300mg are strongly mixed together. After several, preferably 10 minutes ofmixing, the thus obtained mixture is poured into a frit moulding toolprepared especially for this purpose and then pressed therein byapplying a pressure of at least 50 MPa, preferably 250 MPa, to shape asheet with a thickness of 0.25 mm. During the moulding process, the PTFEfilaments get tangled and fused, causing the lead dioxide grains to bejoined at the same time. The resulted lead dioxide/PTFE sheet hascompact dimensions and a continuous surface, it can be easily formedmechanically, and in addition, it is resilient and ductile. Then theanode 16 is prepared by cutting the thus obtained lead dioxide/PTFEsheet to the desired size and shaping it.

When designing the construction of the cell 110′ shown in FIG. 2A andachieved by utilizing the electrode structure 10, and when selecting thematerials for the cell 110′, the chemical resistance against the gaseousmixture of oxygen and ozone and the mechanical strength due to thepressure of the gas generated by electrolysis of water are kept in view.The cell 110′ in its assembled state is composed of a cathode side halfcell 210 and an anode side half cell 215 that are fixed together in aform-fitting and thereby sealed manner. The electrode structure 10 isarranged in a seat 240 formed in the half cell 210 and defined by abottom wall and a side wall, wherein the bearing member 11 of saidelectrode structure 10 (see FIG. 2B) abuts on the bottom wall of theseat 240. The form-fitting abutment is established between the outersurface of a compressive flange 245 of the half cell 215 and the sidewall of the seat 240. The half cell 215 is provided with a depression248 for receiving the anode side of the electrode structure 10, whereinsaid depression 248 is laterally defined by the compressive flange 245.In the assembled cell 110′, the bearing member 18 of the electrodestructure 10 (shown in FIG. 2B) is in close contact with the half cell215 within the depression 248, whereas the compressive flange 245 pushesthe electrode structure 10 to the bottom wall of the seat 240 withfirmly fixing it thereby.

The cathode side half cell 210 is provided with through-holes (notreferenced in the drawings) for receiving a water feeding connector 260,a hydrogen and water discharging connector 262 and a cathode sideelectrical connector casing 230 in a sealed manner. The anode side halfcell 215 is provided with through-holes (not referenced in the drawings)for receiving an ozone/oxygen gas discharging connector 265 and an anodeside electrical connector casing 235 in a sealed manner. The half cells210, 215 are made of a chemically resistant, gas-proof material,preferably some kind of plastic, and formed preferably by injectionmoulding, machining or another shaping process.

There is at least one current conducting member 250 in the electricconnector casing 230 arranged for providing electrical connectionbetween the power supply and the cathode 13 (see FIG. 2B). The currentconductive member 250 is in the form of a member with the capability ofreversible deformation along its longitudinal axis and thereby theexertion of a compressing force; said member 250 is preferably formed asa cylindrical spring. It is also preferred that the electricalconductive member 250 is made of titanium.

There is at least one current conducting member 255 in the electricalconnector casing 235 arranged for providing electrical connectionbetween the power supply and the electrode support 17 (see FIG. 2B). Thecurrent conductive member 255 is in the form of a member with thecapability of reversible deformation along its longitudinal axis andthereby the exertion of a compressing force; said member 255 ispreferably formed as a cylindrical spring. It is also preferred that theelectrical conductive member 255 is made of platinum. The use ofelectrical conductive members 250, 255 formed as resilient parts allowsto eliminate the changes in dimension due to size deviations andtemperature fluctuations.

The external walls of the half cells 210, 215, i.e. the walls notcontacting with the electrode structure 10, are provided with a cathodeside confining plate 220 and an anode side confining plate 225,respectively. The confining plates 220, 225 serve for protecting thehalf cells 210, 215 against the external mechanical impacts.Accordingly, the confining plates 220, 225 are made of a material withhigh mechanical strength, preferably of stainless steel. The waterfeeding connector 260, the hydrogen and water discharging connector 262and the cathode side electrical connector casing 230 are firmly (but ina releasable manner) fixed into through-holes (not shown in thedrawings) formed in the confining plate 220. Similarly, the ozone/oxygengas discharging connector 265 and the anode side electrical connectorcasing 235 are firmly (but in a releasable manner) fixed intothrough-holes (not shown in the drawings) formed in the confining plate225. Finally, in order to hold the cell 110′ in one piece, to seal theelectrode structure 10 constituting the central part of the cell 110′and to provide the required electrical and mechanical contacts betweenthe parts of the cell 110′ within the half cells 210, 215, through-bolts285 are arranged in through-holes formed in the half cells 210, 215 andin the confining plates 220, 225 and said through-bolts 285 are fastenedby screw nuts 290.

Regulation of the amount of ozone generated takes place by the magnitudeof the direct current used for the electrolysis. The pressure of thegaseous ozone generated is preferably 1 to 50 bar, more preferably atmost about 30 bar, before its feeding into the uniting element 120.Provision of the ozone source 110 as one or more electrolysis cells 110′makes the hazardous process of ozone handling highly safe. Furtherembodiments of the ozone source 110 applicable as part of the ozonolysisapparatus 100 according to the invention are disclosed in detail in aninternational patent application under the PCT, entitled “Ozonegenerating electrolysis cell” filed on the same international filingdate as that of the present patent application.

In its simplest form, the first reactor 130 constituting a firstreaction section of the reactor unit is formed as a preferably tubularclosed (preferentially cylindrical) member having a reaction channel 135provided with an inlet and an outlet. The diffusion limited reaction ofthe sample solution and ozone, i.e. the ozonolysis reaction planned,takes place in the reactor 130, or rather within the reaction channel135 thereof. The first reactor 130 is equipped with a primarytemperature adjusting means 132 in heat transfer or heat exchangerelation with the reaction channel 135. The temperature adjusting means132 performs setting of a desired temperature of the sample solutioncontaining the ozone bubbles. A preferred embodiment of the temperatureadjusting means 132 is in the form of e.g. heating/cooling strands woundaround a given section of the reaction channel 135 or a cascaded-typePeltier unit in contact with a given section of the reaction channel 135through the wall thereof. The temperature adjusting means 132 isconnected to the control unit 190 through an electric lead 136. Thetemperature adjusting means 132 is operated by the control unit 190through the electric lead 136 on basis of the signal provided by atemperature sensor (not shown in the drawings) continuously measuringthe temperature within the reactor 130.

In its simplest form, the second reactor 150 constituting a secondreaction section of the reactor unit is formed as a preferably tubularclosed (preferentially cylindrical) member having a reaction channel 155provided with an inlet and an outlet. The chemical reaction of theintermediate/ozone/oxygen mixture leaving the reactor 130 and theadditive added thereto in the uniting element 140, i.e. thedecomposition/stabilization reaction of the intermediate, takes place inthe reactor 150, or rather within the reaction channel 155 thereof. Thesecond reactor 150 is equipped with a primary temperature adjustingmeans 152 in heat transfer or heat exchange relation with the reactionchannel 155. The temperature adjusting means 132 performs setting of adesired temperature of the mixture of the intermediate and the additive.A preferred embodiment of the temperature adjusting means 152 is in theform of e.g. heating/cooling strands wound around a given section of thereaction channel 155 or a cascaded-type Peltier unit in contact with agiven section of the reaction channel 155 through the wall thereof. Thetemperature adjusting means 152 is connected to the control unit 190through an electric lead 156. The temperature adjusting means 152 isoperated by the control unit 190 through the electric lead 156 on basisof the signal provided by a temperature sensor (not shown in thedrawings) continuously measuring the temperature within the reactor 150.Temperatures within the reaction channels 135, 155 of the reactors 130,150, respectively, can be controlled independently of one another bymeans of the control unit 190.

In embodiments of the first 130 and second 150 reactors formed as simpletubes the inner diameters of the reaction channels 135, 155 arepreferably at most 4 to 5 mm, while the lengths of the reaction channels135, 155 are generally 30 to 100 mm, more preferably 40 to 50 mm. Ingeneral, the lengths of the reaction channels 135, 155 are preferablychosen to enable the accomplishment of the reactions planned in thereaction mixture entered through the inlet while said mixture passesthrough the reaction channel.

The first reactor 130 is connected into between suitably formed sectionsof the pipes 106 and 107 in a removable manner, preferably by adetachable connection. Similarly, the second reactor 150 is connectedinto between suitably formed sections of the pipes 107 and 108 in aremovable manner, preferably by a detachable connection, too.Accordingly, in a possible embodiment of the reactors 130, 150 theinlets and the outlets of the reaction channels 135, 155 are threadedand connected into between the pipes 106 and 107 and/or the pipes 107and 108, respectively, by flare joints with making use of appropriatesealings.

FIGS. 3A and 3B illustrate a further possible embodiment of the first130 and second 150 reactors used in the ozonolysis apparatus 100 in theform of a microfluidic reactor 130′. Said microfluidic reactor 130′ isof a particular construction and can be manufactured with low costs.

In the prior art, the term “microfluidic reactor” commonly refers to asealed channel provided with an inlet and an outlet and used toaccommodate a reaction mixture flowing continuously or intermittentlywith short periods of temporary stops, wherein the dimension of saidchannel perpendicular to the direction of flow of the reaction mixturedoes not exceed 0.5 mm. The microfluidic reactor 130′ illustrated inFIG. 3A comprises a reactor sheet 320 defined by a first face 320A and asecond face 320B, a first limiting member 310 in contact with the firstface 320A of the reactor sheet 320, a closing member 330 covering thesecond face 320B of the reactor sheet 320, a supporting member 340 incontact with the closing member 330 along its peripheries and a secondlimiting member 360 abutting on the face of the supporting member 340opposite to the closing member 330. The closing member 330, thesupporting member 340 and the limiting member 360 together define acooling chamber 353 therebetween. Within the cooling chamber 353, atemperature control unit 350 is arranged in contact with the closingmember 330. The temperature control unit 350 is firmly fixed in itsplace by the supporting member 340. In this arrangement, the temperaturecontrol unit 350 is separated from the second limiting member 360 by aclearance, that is, the temperature control unit 350 and the secondlimiting member 360 do not contact each other. The cooling chamber 353is in communication with the external environment through preferablythreaded through-holes 367, 369 formed in the second limiting member360.

The first and second limiting members 310, 360 serves for holdingtogether the elements arranged therebetween and protecting them againstexternal mechanical impacts. Accordingly, the limiting members 310, 360are made of steel, for example stainless steel, of high mechanicalstrength. The limiting member 310 is further provided with through-holes(not shown) to allow communication between the external environment andthe channel formed in the reactor sheet 320. One of the through-holes367, 369 receives a coolant feeding means 357 opening into a flowchannel 355 defined by the clearance adjacent to the temperature controlunit 350 of the reactor 130′ in a sealed and releasable manner. Thesealed connection of the coolant feeding means 357 is provided by agasket 358 arranged between the limiting member 360 and the coolantfeeding means 357 itself. The gasket 358 is preferably formed as anO-type ring. The other one of the threaded through-holes 367, 369 formedin the limiting member 360 is adapted to receive a coolant dischargingmeans 359 in a sealed and releasable manner, wherein said coolantdischarging means 359 opens from the clearance 355. The sealedconnection of the coolant discharging means 359 is provided by a gasket(not shown in the figures) arranged between the limiting member 360 andthe coolant discharging means 359 itself, wherein the gasket ispreferably formed as an O-type ring.

The reactor sheet 320 is made of a chemically resistant, easilymachinable heat-resistant material. The material of the reactor sheet320 is a chemically resistant plastic material, preferably a fluorinatedand/or chlorinated polymer, more preferably PTFE. The reaction channel325, that is used to ensure a proper space for the reactants or themixture thereof during the operation of the reactor 130′, as well as toaccommodate the chemical reaction planned (i.e. the ozonolysis reactionor the reaction for decomposing/stabilizing the intermediate), is formedin the face 320B of the reactor sheet 320; details of the reactionchannel 325 are shown in FIG. 3B.

As it can be seen from FIG. 3B the reaction channel 325 is provided withpass-throughs 390, 392, 394 in flow communication with connectors 380,382, 384, respectively, mounted into through-holes of the limitingmember 310. The pass-throughs 390, 392 are used to feed the reactants,whereas the pass-through 394 is used to discharge the reaction productof the chemical reaction talking place in the reaction mixture producedby an uniting element 329 having an Y-shape and serving as a mixerintegrated into the reaction channel 325. The length of a section of thereaction channel 325 extending between the uniting element 329 and thepass-through 394 is chosen in such a way that the desired chemicalreaction of the reactants getting into contact with one another due tothe uniting element 329 be performed before the reactants reach thepass-through 394. As shown in FIG. 3B, in order to facilitate the designof the reactor 130′ with reduced dimensions, the reaction channel 325consists of relatively long sections running in parallel and relativelyshort sections running perpendicularly to the former ones. Anotheradvantage of this topology of the reaction channel 325 is that thetemperature of the reactants/reaction mixture can be changed quickly andreliably due to the large ratio of the channel surface to the channelvolume.

The reaction channel 325 is formed in the face 320B in such a mannerthat after properly clamping the reactor sheet 320, a machining toolwith a rolling machining surface—preferably a ball-type machiningtool—is pressed onto the face 320B by applying a compressive forcechosen depending on the material and the plasticity of the reactor sheet320, wherein said rolling machining surface is guided, according to aprogram, in a guiding (or controlling) device put onto the place of thelimiting member 310. The value of the applied compressive force ischosen to cause the ball of the machining tool to intrude into the bodyof the reactor sheet 320 to an extent of the entire desired depth of thereaction channel 325 to be formed. The reaction channel 325 is thenformed by continuously advancing the ball-type machining tool along apredetermined path of the required reaction channel 325 according to anappropriate adjustment of the control, wherein the rate of advance istypically in the range of 0.1 to 5 mm/sec. During the continuousadvancing motion of the machining tool with the rolling machiningsurface, the material of the reactor sheet 320 is getting dense alongthe peripheries of the reaction channel 325 and due to the shearingforces arising becomes squeezed out, which results in the formation of asealing edge along each of the opposite peripheries of the reactionchannel 325. Dimensions of the reaction channel 325 and the sealingedges depend on the diameter of the machining surface of the machiningtool. In particular, if said ball-type machining tool is used, the widthof the reaction channel 325 and the size of the sealing edges formedtogether with the reaction channel 325 can be adjusted by changing thediameter of the ball of the machining tool. The depth of the reactionchannel 325 may be adjusted by changing the height position of the ballof the ball-type machining tool.

Sealing of the reaction channel 325 formed in the reactor sheet 320 iscarried out by placing the closing member 330 onto the face 320B or thesealing edges projecting therefrom, and by applying a compressive forceperpendicular to the plane of the closing member 330. Due to the appliedforce, the sealing edges become deformed that results in a sealed jointbetween the reactor sheet 320 and the closing member 330. It should benoted that in this case, the compressive force is distributed only overthe sealing edges of the face 320B, instead of the whole face 320B,which yields more reliable sealing. For the closing member 330, asheet-like member/film made of a material with good thermal conductivityand chemical resistance, as well as having smooth surfaces is used. Ifgood thermal conductivity is an essential requirement, the closingmember 330 is made of a PTFE film with a thickness of up to 20 μm.

After sealing the reaction channel 325, the reactor sheet 320 isprovided with through-holes in the full thickness of the reactor sheet320 at the pass-throughs 390, 392, 394 in order to allow thecommunication between the connectors mounted into the limiting member310 and the pass-throughs 390, 392, 394.

It is preferred that the supporting member 340 is in the form of asquare frame made of aluminum.

The temperature control unit 350 accommodated within the supportingmember 340 is arranged at an opposite surface of the closing member 330relative to the reaction channel 325, in a position where it is incontact with the closing member 330, as shown in FIG. 3A. A preferredembodiment of the temperature control unit 350 is preferably formed as acascaded-type Peltier-unit (comprising a plurality of, but preferablytwo Peltier-elements in contact with one another), the operation ofwhich is based on the Peltier-effect. As it is obvious for one skilledin the art, a Peltier-element is a device comprising two thin ceramicsheets and a plurality of semiconductor sheets therebetween, whichprovides a constant difference of temperature between its two sides whenan appropriate current and voltage is applied on the device. In itssimplest form, there are two different metal layers on the bottom sideof the Peltier-element through which a current is flowing which resultsin a thermal flow between the metal layers. Thus a cold side and a warmside are obtained. The cold side of a first Peltier-element 351 of thetemperature control unit 350 used in the microfluidic reactor 130′ is incontact, through the closing member 330, with the reactor sheet 320 orthe reactants/reaction mixture accommodated within the reaction channel325. At the same time, the warm side of the first Peltier-element 351 ofthe temperature control unit 350 used in the microfluidic reactor 130′is in contact with the cold side of a second Peltier-element 352. Thetemperature control unit 350 used to control the temperature of thereactor 130′ is formed by an integrated unit of the two aforementionedPeltier-elements 351, 352, preferably within a common casing.

The first limiting member 310, the reactor sheet 320, the closing member330 and the supporting member 340 of the temperature control unit 350 ofthe microfluidic reactor 130′ are held and clamped together by anappropriate fastening mechanism in order to create and maintain aperfect seal between the reactor sheet 320 and the closing member 330.The fastening mechanism is preferably formed by through-bolts 370inserted into through-holes (not shown) formed in each one of said partsand crossing over the entire thickness of the reactor 130′, and by nuts372 screwed thereon.

In the microfluidic reactor 130′ applicable within the ozonolysisapparatus 100 according to the invention, the entire surface used toform the fluidic construction is 25 cm², the channel has a length of 65mm, the average diameter of the channel is 400 μm, the depth of thechannel is also 400 μm, the number of inlets and outlets is three, asingle uniting element is used, the lowest reachable temperature withinthe channel is −50° C. (at a thermal load of +5 W), the highestreachable temperature within the channel is 350° C., the maximumoperational pressure of the reactor is 30 bar, and the maximum rate ofchange in temperature is 8° C./sec (within the range of 0 to 20° C.).

Possible further embodiments of the reactors 130, 150 of the ozonolysisapparatus 100 according to the invention are disclosed in detail in aninternational patent application under the PCT, entitled “Method offorming a sealed channel of a microfluidic reactor and a microfluidicreactor comprising such channel” filed on the same international filingdate as that of the present patent application. It should be noted thatin case of the microfluidic reactor 130′ shown in FIGS. 3A and 3B isused as the reactors 130, 150, the uniting elements 120, 140 areintegrated into the reaction channel 325 formed in the microfluidicreactor 130′ and hence there is no need to use such further elements. Insuch a case, the outlet of the feed pump 102 and the outlet of thedispensing valve 112 are connected directly to the inlets of themicrofluidic reactor 130′ forming the first reactor 130, whereas theoutlet of the feed pump 172 and the outlet of the reactor 130 areconnected directly to the inlets of the microfluidic reactor 130′forming the second reactor 150. Moreover, when using said microfluidicreactor 130′, the temperature adjusting means 132, 152 are provided bythe microfluidic reactor's 130′ own temperature control unit 350.

A possible yet further embodiment of the second reactor 150 can beprovided in the form of a packed column with a reactive charge. In sucha case, the reactive charge preferably contains the additive requiredfor the decomposition/stabilization reaction of the intermediate insolid phase, and hence there is no need to supply a liquid phaseadditive. As such packed columns, e.g. the replaceable cartridgereactors disclosed in International Pat. Appl. No. PCT/HU2005/000090 canbe preferentially used.

The pressure adjusting means 160 is an electronically controlled, motordriven precision pressure adjusting valve that is arranged at the end ofthe flow path and adjusts the pressure needed for the ozonolysisreaction and maintains it at a constant value within the flow path. Thepressure adjusting valve, in consequence of its construction, is highlysensitive and is capable of setting the value of the pressure inextremely tiny steps, i.e. almost continuously. The operational range ofthe pressure adjusting means 160 ranges from 1 bar to 100 bar,preferably from 10 bar to 30 bar. The pressure adjusting means 160 isactuated by the control unit 190 by means of appropriate trigger signalssent via the electrical lead 197.

The pipes 106, 107, 108, 114, 176 are formed as capillaries with innerdiameters falling within the range of 0.05 to 5 mm, preferably of 0.05mm and made of a pressure-proof and chemically resistant material.

As it is shown in FIG. 1, a possible further embodiment of theozonolysis apparatus 100 according to the invention is also equippedwith a secondary temperature adjusting means 185. The secondarytemperature adjusting means 185 is in heat transfer relation with theprimary temperature adjusting means 132 of the first reactor 130 and/orthe primary temperature adjusting means 152 of the second reactor 150via heat exchangers 186 and 187, respectively. (When a microfluidicreactor 130′ shown in FIG. 3A is used as each of the reactors 130, 150,the heat exchangers 186, 187 are in heat transfer relation with thereactors' own temperature control units 350.) On the other part, thesecondary temperature adjusting means 185 is in heat transfer/heatexchange relation with its external environment. The secondarytemperature adjusting means 185 is operated by the control unit 190 bymeans of appropriate trigger signals sent via an electrical lead 189.

In what follows, operation of the laboratory scale ozonolysis apparatus100 is discussed in detail.

After starting the ozonolysis apparatus 100, as a response to a signalfrom the control unit 190, the feed pump 102 commences to feed thesample solution from the liquid reservoir 104 through the pipe 106 intothe flow path at a previously set constant flow rate falling preferablybetween 0.1 ml/min and 10 ml/min, and typically being 0.25 ml/min.Simultaneously, as a response to a first signal from the control unit190, the dispensing valve 112 opens, then as a response to a secondsignal following the first one within a relatively short period of timeit closes and then repeats this opening-closing operation until itreceives a different command from the control unit 190. As a consequenceof the opening-closing operation of the dispensing valve 112, doses ofgiven amounts of gaseous ozone are delivered one after the other fromthe ozone source 110 through the pipe 114 into the flow path. Tomaintain feeding of ozone, the pressure of the gaseous ozone flowingthrough the pipe 114 will be all the time higher than the pressure ofthe sample solution flowing through the pipe 106. Simultaneously withthe very first opening of the dispensing valve 112, the pressureadjusting means 160—as a response again to a signal from the controlunit 190—closes to build up a pressure prescribed in the flow path (andrequired by the ozonolysis reaction). The sample solution supplied andthe gaseous ozone meet in the uniting element 120 wherein they getmixed. The sample solution containing ozone bubbles flows via the outletof the uniting element 120 into the first reactor 130 through the pipe106. Within the reaction channel 135 of the reactor 130, temperature ofthe sample solution containing ozone bubbles is set to the desired valueby the temperature adjusting means 132 under the supervision of thecontrol unit 190. Meanwhile, the sample solution fed into the reactor130 progresses towards the outlet of the reactor 130 in the reactionchannel 135. During the progression, the desired ozonolysis reactiontakes place within the reaction channel 135. The extension of reactionto the whole sample solution within the reaction channel 135 is assuredon the one part by adjusting/maintaining the temperature within thereaction channel 135 and on the other part by means of the pressuremaintained in the flow path by the pressure adjusting means 160. Theintermediate that is produced from the sample solution passing throughthe reaction channel 135, optionally mixed with gaseous ozone andoxygen, flows through the output of the reactor 130 and the pipe 107into the uniting element 140. Simultaneously with this, as a response tothe signal from the control unit 190, the solution of additive is fed ata preset flow rate from the liquid reservoir 174 to the other inlet ofthe uniting element 140 by the feed pump 172. Within the uniting element140, the intermediate mixes with the solution of additive. From theuniting element 140, the mixture of the intermediate and the solution ofadditive enters the second reactor 150, within the reaction channel 155of which the decomposition/stabilization reaction of the intermediatetakes place at a temperature set by the temperature adjusting means 152under the supervision of the control unit 190. The mixture of the finalproduct, ozone and oxygen leaving the outlet of the reactor 150 entersthe product receptacle 180 through the pressure adjusting means 160. Bymeans of suitable units, hazardous ozone is extracted from the mixturebeing discharged into the product receptacle 180 and is eitherdestructed by e.g. heating or via catalytic processes or recirculated tothe outlet of the ozone source 110. Meanwhile, the oxygen content of themixture simply escapes to the environment.

Besides the structural elements required for accomplishing theozonolysis reaction, the ozonolysis apparatus 100 according to theinvention is also equipped with a display unit (not illustrated in thedrawings) and with a keyboard for data input. Operation of theozonolysis apparatus 100 according to the invention and of the unitsthereof is assured by a direct current power supply not shown in thedrawings.

The total volume of the continuously connected flow path of theflow-type laboratory scale ozonolysis apparatus 100 according to theinvention is at most 50 cm³, more preferably at most 25 cm³.

It is apparent for a person skilled in the relevant art that a greatnumber of modifications of the ozonolysis apparatus 100 are possible,and furthermore the apparatus itself can be equipped with furtheradditional units. In particular, one of the modifications relates to theozone source 110; the ozone source 110 can be also implemented e.g. witha unit measuring the concentration of the gaseous ozone generated by theozone source 110 itself and/or with a drying unit decreasing the watercontent of the gaseous ozone generated by the ozone source 110 itself.The drying unit might preferably be a freezing-out type drying unit.

In what follows, the ozonolysis apparatus 100 according to theinvention, as well as its application and advantages will be illustratedby examples. The ozonolysis apparatus 100 according to the invention isespecially suitable for accomplishing the reactions of the examples. Thereason for this is that in case of reactions taking place in theheterogeneous phase (gas/liquid) the length of the vital contactingperiod and the size of the contacting surface can be controlled. Inaddition to this, most of the ozonolysis reactions require theapplication of temperatures below the room temperature, and in most ofthe reactions the further chemical process of the ozonides also requiresa cooled environment. As exothermic reactions take place here, it isessential to divert the heat of reaction rapidly and in a reliablemanner which is facilitated to a great extent by the temperatureadjusting system used in the ozonolysis apparatus 100 according to theinvention. Since in case of an ozonolysis apparatus 100 according to theinvention a well-defined period of time elapses between the chemicalreaction for producing the ozonide and the chemical reaction fordecomposing it (as the mixture leaving the first reactor 130 shouldreach the uniting element 140), the appearance of side reactions can bedecreased to a great extent, i.e. the target compound can be produced atmuch higher yields.

EXAMPLE 1

A solution (1:1) of 5-metil-1-H-indol in methanol/dichloromethane with aconcentration of 0.025 mol/l is fed into the reaction channel 135 of afirst reactor 130 provided as the microfluidic reactor by means of thefeed pump 102 from the liquid reservoir 104 of the ozonolysis apparatus100. Furthermore, a gaseous mixture of ozone and oxygen with a constantamount of 5% volume by volume ozone is fed into the reaction channel 135of the first reactor 130 provided as the microfluidic reactorillustrated in FIG. 3A by means of a controlled actuation of thedispensing valve 112. Said reactants can mix within the reaction channel135. The flow rate of the solution of the 5-metil-1-H-indol through thereactor 130 is kept constant at 0.25 ml/min, wherein a pressure of 5 baris continuously maintained within the reactor 130 during the entireprocess. The reaction is performed at the temperature of 0° C. Themixture with an ozonide content led out from the reactor 130 is directedinto the reaction channel 155 of a second reactor 150 through the pipe107. Here the second reactor 150 is formed e.g. as a tubular reactorproviding a reaction channel 155 with an inlet and an outlet andcontaining sodium borohydride (NaBH₄) in an immobilized form. Thereaction is performed at the temperature of −15° C. The second reagentNaBH₄ ensures the decomposition of the intermediate of the reaction (theozonide produced). The average residence time within the reactor 150 isin the order of seconds. The reaction product is N-(2-hydroxymethyl-4-methyl-phenyl)-formamide. According to a high-pressure liquidchromatography (HPLC) analysis, the degree of purity of the reactionproduct is 98%.

The yield of reactions performed by conventional reactors is about 60 to65%, which primarily comes from the difficultly controllable reactionconditions and thus from the proportion of the side products of thereaction [see for example the Journal of the Chemical Society (1953),pp. 3440-3443 or the Journal of the Chemical Society (1950), pp.612-618]. In case of a reaction accomplished under improved conditions,the yield decreases in proportional to an increase in the degree ofpurity.

EXAMPLE 2

Our study of continuous flow ozonolysis with an ozonolysis apparatus 100according to the invention involves two major groups of compounds:aromatic hydrocarbons and indoles. The ozonolysis of these species via“classical” methods and the results thereof are well-known. After theozonolysis, a reductive workup is chosen to quench the intermediates.For this, a reactor 150 filled with sodium borohydride proved to be thebest choice. The results obtained under the applied conditions show thatneither the reaction rate nor the level of selectivity of the ozonolysisperformed by the ozonolysis apparatus 100 according to the inventiondepends on temperature. This conclusion is supported by the experimentscarried out both for stilbene and indole: the distribution of productsis the same at the temperatures of −40° C., −20° C., 0° C. and 20° C.Using excess olefin over the ozone, the extent of conversion remains thesame at all temperatures applied (Table 1). This invariability ofconversion at various temperatures indicates that no considerablesecondary or side reaction takes place with a rate of the same order ofmagnitude as that of the ozonolysis reaction within the ozonolysisapparatus 100 according to the invention.

TABLE 1 Conversions of indole measured during ozonolysis reactionsthereof performed at different temperatures (c = 0.05M). T (reactor, °C.) conversion (%) −60 20 −40 60 −20 60 0 60 20 60

According to the literature of ozonolysis reactions, to avoid undesiredside reactions, vast majority of such type of reactions should beperformed at low temperatures. In light of this, it was unexpected inour studies carried out by making use of the ozonolysis apparatusaccording to the invention that the extent of conversion is independentof the temperature within the reactor. This fortuitous finding clearlymeans that various ozonolysis reactions can be performed preferably evenat ambient temperature by means of the ozonolysis apparatus according tothe invention without a decrease in the extent of conversion.

In particular, the ozonolysis of stilbene and tetraphenyl-ethylenewithin the ozonolysis apparatus 100 according to the invention atambient temperature results in benzylalcohol and diphenyl carbinol,respectively, as main products. The extents of conversion for saidreactions are collected in Table 2.

TABLE 2 reactant/olefin conversion at ambient temperature (%) stilbene90 tetraphenyl-ethylene 90

The results of the above discussed experiments prove that the ozonolysisapparatus according to the present invention—contrary to the apparatusesfor performing ozonolysis reactions which belong to the prior art andare used nowadays—has an excellent heat transfer coefficient. As theconsequence of its excellent heat-removal capability, the ozonolysisapparatus according to the invention thus assures the removal of heatgenerated within the reactor during the reaction at a proper rate evenin case of exothermic reactions accompanied by intensive generation ofheat, and thereby it inhibits the over-heating of the reaction mixtureand hence the start and course of undesired side reactions. On thecontrary, traditional reactors are unable to provide heat-removal ofsufficient rapidity, and hence to avoid side reactions when using atraditional reactor an overcooling and then a slow heating of thereaction mixture is required. This leads to an increase in the timeperiod needed for the target reaction to take place, and furthermore itundesirably decreases the rate of reaction.

1. A flow-type laboratory scale ozonolysis apparatus for performingozonolysis reaction of a given substance, the apparatus (100) comprisinga liquid reservoir (104), a feed pump (102) in the form of a liquid pumpgenerating a constant volume flow rate, a uniting element (120) with twoinlets and an outlet, a reactor unit and a pressure-adjusting means(160), all connected into a flow path, the apparatus (100) furthercomprising an ozone source (110) and a dispensing valve (112)transmitting a gas stream only in a single direction and being installedbetween the ozone source (110) and one of the inlets of the unitingelement (120), wherein the pressure-adjusting means (160) is arrangedafter the reactor unit and is provided with an electrically governedcontrol, characterized in that the liquid reservoir (104) contains atleast the substance, as a solute, to be subjected to the ozonolysisreaction and the reactor unit consists of first and second reactor zonesbeing different as to their function, wherein the outlet of the firstreactor zone is connected to the inlet of the second reactor zone in theflow path and a substance intake is inserted into the flow path betweenthe reactor zones, and wherein the ozone source (110) is provided as anozone source generating ozone in-situ by electrolysis and wherein thetotal inner volume measured along the flow path between the feed pump(102) and the pressure adjusting means (160) is at most 50 cm³.
 2. Thelaboratory scale ozonolysis apparatus (100) of claim 1, characterized inthat the reactor zones of the reactor unit are provided as physicallyseparate first and second reactors (130, 150).
 3. The laboratory scaleozonolysis apparatus (100) of claim 2, characterized in that the firstreactor (130) is provided with a temperature adjusting means (132) inheat transfer relation with the reactor (130).
 4. The laboratory scaleozonolysis apparatus (100) of claim 2, characterized in that the secondreactor (150) is provided with a temperature adjusting means (152) inheat transfer relation with the reactor (150).
 5. The laboratory scaleozonolysis apparatus (100) of claim 2, characterized in that thesubstance intake is formed as a uniting element (140) with two inletsand an outlet, wherein the outlet of the first reactor (130) isconnected to one of the inlets of the uniting element (140), the inletof the second reactor (150) is connected to the outlet of the unitingelement (140) and a second liquid reservoir (174) is connected to theother inlet of the uniting element (140) through a second feed pump(172), wherein the second liquid reservoir (174) contains at least anadditive needed for the completion of ozonolysis reaction.
 6. Thelaboratory scale ozonolysis apparatus (100) of claim 5, characterized inthat the first reactor (130) is provided as a microfluidic reactor(130′) having an inlet, an outlet and a reaction channel (325) foraccommodating chemical reactions, the microfluidic reactor (130′)comprising a sealed reaction channel (325) prepared in the surface of areactor sheet (320) by cold forming and sealed by a closing member (330)pressed onto said surface of the reactor sheet (320) and a temperaturecontrol unit (350) arranged in contact with a surface of the closingmember (330) opposite to the reaction channel (325) and being in heattransfer relation with the reaction channel (325) through the closingmember (330).
 7. The laboratory scale ozonolysis apparatus (100) ofclaim 6, characterized in that the uniting element (120) is formed as anintegral member of the reaction channel (325).
 8. The laboratory scaleozonolysis apparatus (100) of claim 6, characterized in that thetemperature adjusting means (132) is provided by the temperature controlunit (350).
 9. The laboratory scale ozonolysis apparatus (100) of claim2, characterized in that the second reactor (150) is provided as amicrofluidic reactor (130′) with the same construction as that of thefirst reactor (130).
 10. The laboratory scale ozonolysis apparatus (100)of claim 2, characterized in that the second reactor (150) is providedas a packed column with a reactive charge, wherein the charge containsan additive needed for the completion of ozonolysis reaction. 11.(canceled)
 12. The laboratory scale ozonolysis apparatus (100) of claim1, characterized in that the ozone source (110) is provided as at leastone asymmetric pressure ozone generating electrolysis cell (110′). 13.The laboratory scale ozonolysis apparatus (100) of claim 12,characterized in that the ozone generating electrolysis cell (110′)comprises a cathode (13); an anode (16) comprising a mixture of lead(IV) oxide and polytetrafluoroethylene; a membrane (15) arranged betweenthe cathode (13) and the anode (16); and an electrically conducting,liquid and gas permeable first electrode support (17) in contact with aside of the anode (16) located opposite to the membrane (15), said sideof the electrode support (17) having a surface covered with aplatinum-containing layer, wherein the material of the anode (16) is amixture prepared by high-pressure molding of lead (IV) oxide grains ofcolloid size and polytetrafluoroethylene filaments having a dimension ofat most 1 mm.
 14. The laboratory scale ozonolysis apparatus (100) ofclaim 1, characterized in that it further comprises a central controlunit (190) which is connected to the dispensing valve (112), the feedpump (102) and the pressure adjusting means (160) through appropriateelectrical connections.
 15. The laboratory scale ozonolysis apparatus(100) of claim 1, characterized in that the uniting element (120) isprovided with an end sheet at the inlet thereof through which ozone isfed into the flow path, said end plate having perforations to decreasethe size of the ozone bubbles to be introduced.
 16. The laboratory scaleozonolysis apparatus (100) of claim 3, characterized in that thetemperature adjusting means (132) of the first reactor (130) isconnected with the central control unit (190) through an appropriateelectrical connection.
 17. The laboratory scale ozonolysis apparatus(100) of claim 4, characterized in that the temperature adjusting means(152) of the second reactor (150) is connected with the central controlunit (190) through an appropriate electrical connection.
 18. Thelaboratory scale ozonolysis apparatus (100) of claim 16, characterizedin that it further comprises a secondary temperature adjusting means(185) which is in heat exchange relation with the temperature adjustingmeans (132) of the first reactor (130) and/or the temperature adjustingmeans (152) of the second reactor (150), and is connected with thecentral control unit (190) through an appropriate electrical connection.19. A laboratory scale method of performing ozonolysis reaction of asubstance solved in a solvent, comprising the steps of (i) supplying agiven amount of substance being solved to be subjected to ozonolysisreaction into a flow path by means of a feed pump (102) at asubstantially constant volume rate; (ii) feeding ozone by a dispensingvalve (112) into the flow path in a section located after the substancesupplying position in the form of microbubbles, said ozone beingproduced in-situ by electrolysis; (iii) leading solved substance througha reactor unit comprising first and second reactor zones arranged in asection of the flow path located after the ozone feeding position; (iv)supplying an additive needed for the completion of ozonolysis reactioninto the flow path after the first reactor zone of the reactor unit; (v)maintaining the pressure of the reaction in a given pressure range bymeans of a pressure adjusting means (160) arranged in the flow pathafter the reactor unit; (vi) collecting the product generated in thesecond reactor zone of the reactor unit in a product receptacle (180)connected to the end of the flow path, wherein the total inner volumemeasured along said flow path, also including the volume of the reactorunit, is at most 50 cm³.
 20. The laboratory scale method of performingozonolysis reaction according to claim 19, characterized in that theozone is supplied into the flow path intermittently.
 21. The laboratoryscale method of performing ozonolysis reaction according to claim 19,characterized in that the temperature of the solved substance is changedto a prescribed temperature of the reaction to be performed in the firstreactor zone of the reactor unit.
 22. The laboratory scale method ofperforming ozonolysis reaction according to claim 21, characterized inthat a reaction resulting in decomposition or stabilization of theintermediate produced by the reaction performed in the first reactorzone is carried out in the second reactor zone of the reactor unit. 23.The laboratory scale method of performing ozonolysis reaction accordingto claim 22, characterized in that the temperature of the intermediateproduced in the first reactor zone and the temperature of the additivesupplied into the flow path are changed in the second reactor zone ofthe reactor unit to a prescribed temperature of the reaction to beperformed in the second reactor zone of the reactor unit.
 24. (canceled)